Tag Archives: 802.11g

WiFi (802.11G/N) signal strength

Computer Aid Posted on by

WiFi is such a strange beast to work with.

I recently had a customer in a high-set house, who would have the internet dropout fairly often.

The setup was: adsl modem connected to a netgear WGR614 “G” wireless router, 2 WiFi laptops, and a PC downstairs which connected using Wifi (a netgear WG111 USB WiFi adapter).

The wireless router was located at one corner of the reasonable small house, the downstairs PC was almost directly below the router, and the two laptops are in the lounge-room, with the signal having to pass through about 4 thin walls.

I have a similar setup, and have no internet problems.

With the customer, the downstairs PC would work fine, but the two laptops would occasionally lose WiFi signal… When the signal was “re-acquired”, it would show a signal strength of  5 bars (ie very strong signal)…

I tried a few different channels, but that made no difference.

The customer eventually moved the router to a more central place in the house (the kitchen), just 1 room away from the lounge room.

Now, the laptops no longer lose the internet connection, but the downstairs PC can barely connect at all.

So I figure: a newer “N” wireless router should do the trick… lots more coverage, fewer dead spots.

wnr2000I install a Netgear WNR2000, but it ends up having similar coverage (and dead spots) as the WGR614 (despite my using a new WN111 USB wireless adapter in the downstairs PC…)

This is so strange, as the Laptops/PCs don’t detect any other neighboring WiFi signals that could also be causing interference.

I even tested the WNR2000 at home, and I was able to take my laptop down the street, and when I had about 2 houses between the laptop and the router, the signal started to drop out…

In the end, I could only guess that there is a lot of shielding / attenuation causing problems with the 802.11G/N radio signals.

The final solution: put the WiFi router in the kitchen, and get a tech to run a CAT5 Ethernet cable to the room downstairs.

Sometimes, you just can’t beat a wired networking solution!

wireless interference and GlobeSurfer II wifi setup

Computer Aid Posted on by

OK, here is the setup:

  • Laptop (wifi 802.11G capable, wifi currently switched off)
  • Virgin GlobeSurfer II 3G modem/phone access point/wifi access point… wifi currently switched off)
  • Wii console (no wifi setup… yet)
  • Cordless phone (the base is connected to the GlobeSurfer II for standard phone access)

The laptop, Globesurfer II, and cordless phone are on a small table about 60cm X 60 cmglobesurfer2

Laptop connects to the GlobeSurfer II (GS2) via ethernet cable.

GS2 has wifi disabled by default, so to get the Wii console onto the internet, I switch on the GS2 wifi by:

login -> go to connection settings -> network connections -> lan bridge -> Lan wireless -> edit -> setup the SSID, WPA-PSK, password, and save/apply settings.

I then setup the Wii (also pretty standard stuff). The Wii connects, and it does its usual system updates. I also download some extra channels (everybody votes, opera browser, contest channel).

Everything is working well.

I figure: The laptop probably doesn’t need to use ethernet anymore, I’ll switch on its wifi, and get it running without a cable, so the laptop can “roam around the house”. This also works well.

A few minutes later, the customer makes a call with the cordless phone… She hears 2 ring tones, then silence.

She tries again, but no luck.

I try phoning the cordless (house) phone… but I eventually get a busy tone.

I’m told the phone sometimes drops out like this, but starts working again after a few minutes.

30 Minutes later, and the problem isn’t fixed.

I know I didn’t change any phone setting within the GS2, but I take a look anyway.

I find a screen with a call log, and I can see all the failed calls are logged (duration 2 seconds).

Hmmm, I decide to try disabling the GS2 wifi, in case its interfering somehow… but the problem still persists.

Since the GS2 is back to its original setup, Its now looking like a possible Virgin network problem.

I ask the customer to call virgin and ask for help. She says she doesn’t have time now, and will do it later.

The next day, she say she tried to call Virgin, but could only manage to leave a message for them to investigate. In the meantime, she resets the GS2 back to factory default settings, and a few hours later, the phone is working again. So Virgin might have fixed something… or the reset to factory defaults did… not sure which.

She also reads the Virgin Mobile “manual”… and finds an interesting gem of information: wireless devices should not be closer than 30cm.

Now thats something I didn’t know.

So, on a small table, she had the GS2, the cordless phone, and a laptop, all within 30 cm of each other.

Looks like radio interference was the problem.

So she moves the cordless phone further away, and decides to stick with an ethernet cable connecting the laptop to the GS2.

But I’m invited back to try getting the Wii going again…

So I do the same as my first visit (but just in case, I change the wifi channel from 11 to 1 (in case there was any channel contention).

Except for a minor spelling mistake (on my part) on the Wifi wpa password, it all worked well, and its still working a few weeks later.

Its situations like these that that make me wish for a wireless “interference” tester… If there is any wireless interference, I need to resort to trial and error in order to fix the problem.

Cannot use wireless on netgear wpn824

Computer Aid Posted on by

I get an amazing range of problems that I just cannot fix over the phone.

One customer wanted me to help get their laptop to use the wireless router… They already had another laptop that was connected wirelessly, so a second one should be easy.

Well, Once I get him to connect to the router vie IE, I quickly find thet they are using WEP. Given that I’m a lot more familiar with WPA-PSK, and WEP is a lot more “hackable” than WPA, and WPA allows for “friendly” passwords, then I got him to change the router encryption to WPA-PSK.

But it still wouldn’t work.

I tried changing between AES and TKIP, but that still didn’t make a difference.

The second laptop actually started working after a reboot, but not the first laptop… now this should have been a clue to what the problem was.

Anyway, I arrange to go out and take a look first-hand.

After a while, I eventually find the cause: somebody had enabled the routers MAC access control… so only computers with pre-allowed network card IDs are allowed to connect.

I’ve long since given up enabling MAC access control, since its barely a speed hump to a real hacker, whereas good WPA security (with a 20+ character password) is much more secure.

So the moral of the story is: don’t enable MAC access control on wireless routers (use WPA instead).

Cannot discover wireless networks (ad-hoc problem)

Computer Aid Posted on by

I supplied a new PC to a customer.

He was retired, so he saved some money by getting his son to install a corporate XP.

But once he got it back, he couldn’t get the wireless internet link working.

So I pop over, enter the WEP details (the wireless router had been setup a long time ago, so I didn’t want to go change it).

But no matter what I tried, I just couldn’t see any networks to connect to.

So, I figure I haven’t much choice, I’ll need to connect directly to the router via ethernet, and setup a WPA network… I’ve developed a strong dislike for WEP.

So I setup the WPA-PSK settings in the router, reboot, and so far I can see the router.

I disconnect the ethernet cable, but when I try to connect to the wireless network, it just fails silently. No error messages, and no indication that there is a problem.

I check that XP is managing the wireless network connection, DHCP is running correctly, but after looking at countless wireless networks, this one doesn’t want to work properly.

So I find myself doing what I often do in this situation: I start to aimlessly browse the network settings.

Thats when I stumble across the cause:

In the “wireless network connection properties”, click on the “wireless networks” tab, and then click on the advanced button (not the advanced tab, the button near the bottom of the window).

And up pops a seldom used “networks to access” window.

Ordinarily, its set to “any available network”. If I’m setting up XP, I usually change it to “infrastructure networks only”… but in this case, it was set to “ad hoc networks only”.

Obviously there are people out there who still use ad hoc networks (I can’t see the point anymore. It was a useful a when access points were much more expensive, but not anymore).

bigpond 3g and 802.11g wireless conflicts

Computer Aid Posted on by

Customer calls, saying they are having difficulties accessing their email (and other strange dropouts) while using their bigpond 3G usb adapter.

Once I get there, I find its all behaving itself normally… no problems (except for VISTA running on 512MB RAM!).

I try various things to try to force the problem to appear, but the email, web browsing, and updates are faultless.

Customer says when the dropouts happen, they usually need to restart the laptop… but strangely, the laptop works well at other locations. They even have an external antenna for the 3G adapter, so that the signal strength cant be an issue.

I also note that when I connect to the 3G network, it takes about 5-10 seconds to connect… no unusually long delays.

Out of curiosity, I look at vistas available networks, and besides the 3G network, it can also see a weak, unsecured 802.11G wireless network… and this is where all the symptoms start to make sense.

I know that XP (and I extrapolate that VISTA has the same weird behaviour) will sometimes prefer to connect to a very weak wireless network rather than other networks (sometimes even ignoring wired ethernet!).

I’m told a neighbor has a wireless router (I reckon its the unsecured network I saw on the laptop).

What I think has been happening, is that the laptop will connect using 3G, and then decide to automatically switch connection to the 802.11G network next door… So now emails refuse to work, as the neighbor is with a different ISP, and web browsing can be badly affected.

What could also happen, is that the laptop connects to 802.11G before it gets manually connected to 3G, so some leftover 802.11G settings cause problems with the 3G internet.

The solution is very easy: push the wireless enable/disable button on the laptop, and the 802.11G network/antenna is disabled.

windows xp service pack 1 (sp1) and 802.11G wireless problems

Computer Aid Posted on by

I return to the vet, & after another check, I find I have no option but to setup wireless at his house & setup the office with a wireless card.

The house is easy (the PC runs win 2000, so I switch it from using usb to ethernet broadband access). I place the modem/wireless router on the windowsill, hoping that the signal will be strong enough to reach the office.

I install a d-link g510 pci card into the office pc, but installing the drivers causes some problems (the dlink wireless utility doesn't want to start). I get the latest driver & I also realise that I need to install the drivers before plugging in the card (whatever happened to plug and play?). So: uninstall the drivers, reopen the pc, remove the card, start the pc, install the latest drivers, shutdown, plugin the card, close the pc, start the pc, and hey, the dlink drivers start correctly (grumble grumble).

Now I go to setup the wireless security, and… hmmm, the windows xp wireless tabs & options look a bit different, somethings like wpa security don't exist!

Ok, I'll try the dlink utility instead… everything is setup correctly, but the link adaptor remains disconnected…

I eventually realise that the PC is running xp SP1. Do I want to do an SP2 upgrade on this computer? After some thought, I decide to go ahead… the risks are minimal, & it should be done sooner or later anyway.

The install takes about 40 or 50 minutes, and after the reboot… yippee, I can get a wireless connection. Signal strength is 40% – 50%, which is fine, since I am running a wireless system myself, which sits at 25% – 35%, but no noticeable dropouts.

I try a ping to an internet website: no response, I ping the wireless router: its fine.

I reboot: still no internet.

Its getting late again (and the vet is getting busy with customers, so I decide to hand back the PC & arrange for another visit).

At this stage, I feel I'm so close to getting the internet working… probably just a simple setting somewhere. Or it might just start working spontaneously a few minutes after I leave.